In a previous discussion, Monsen sagely provided:... if you use Shaded Polygon to change the angle of your floor, and you don't want the sun to affect it at all, you just wish to angle it, after using the Shaded Polygon command on it, you can use the EDITSHADING command on it, and enable the 'Shade Only Copy' option. This will result in rotated fill, but it doesn't get affected by the sun angle (so the pitch becomes irrelevant) and it keeps the same coloration.

EDITSHADING does not work for me. CC3+ prompts me in the command line to pick a shaded entity but when I do and then select Do It, I get a message that reads, "Group does not contain a shaded entity." I'm using CC3+ v3.78, after Update 13. I honestly can't remember if it worked for me with Update 11 (I didn't install 12).

Yes. I used the map that I made as the setup for my Shaded Polygon (Angle by Edge) video, which has two shaded polys on it already. But after I got the error a couple of times, I created a brand new shaded poly and got the same error. Very weird.